Universal gyroscope-suspension system



May 10, 1949. PHNR 2,469,782

UNIVERSAL GYROSCOPE-SUSPENSION SYSTEM Filed Nov. 5, 1945 4 FIG. 1

LONGITUQINAL. VEHICLE AXIS FIG. 10,

D I OI o AMPLIFIER E 2 I N VEN TOR.

35/ COMPASS TRANSMITTER ATTORN EYS .GQMPASS HAR W. PHAIR STABILIZED o &

REPEATER f 36 BM Patented May 10, 1949 UNEVERSAL GYROSCOPE- SUSPENSION SYSTEM Harry W. Phair, Lyndhurst, N. 5., assignor to Fairchild Camera and Instrument Corporation, a corporation of Delaware Application November 5, 1945, Serial No. 626,595

(Cl. V i-5.47)

6 Claims.

This invention relates to universal gyroscopesuspension systems and, while it is of general application, it is particularly adapted for embodiment in such systems of the type which indicates or controls the attitude of a mobile vehicle, such as an airplane or a ship.

In the operation of gyroscope systems for indicating and controlling the attitude of a mobile vehicle, it has been found that, under certain conditions, for example in the diving of an airplane, the normal to the plane including the nrmal pivotal axes of the gimbal support deviates widely from the spin axis of the gyroscope and, in extreme cases, the gimbal ring tends to become coplanar with the spin aXis. When this condition is reached or approached, the behaviour of the gyroscope becomes erratic and unreliable.

It has heretofore been proposed to mount the gimbal ring pivotally within an outer or auxiliary gimbal ring about an axis normally coinciding with a pivotal axis of the gyroscope element in the main gimbal ring and to provide a followup system responsive to deviation of the main gimbal ring about such axis for rotating the auxiliary ring by an equal amount and in the opposite sense so as to maintain the plane of the gimbal ring approximately normal to the spin axis of the gyroscope element. However when such an arrangement is installed on an aircraft with the pivotal axis of the gyroscope element in the main gimbal ring parallel to the longitudinal axis of the craft, if the craft in extreme maneuvers passes through the vertical position, that isthrough the position of an alignment of the auxiliary gimbal ring with the spin axis of the gyroscope element, the followup system reverses sense. As a result, deviation of the main gimbal ring from a plane normal to the spin axis gives rise to a rotational adjustment of the auxiliary gimbal ring in a sense to increase such deviation rather than in a sense to compensate therefor, thus rendering the system effectively inoperative.

It is an object of the present invention, therefore, to provide an improved system for universally supporting a gyroscope from a mobile vehicle which avoids the above-mentioned disadvantages of the arrangements of the prior art and is simple and reliable in operation.

It is another object of the invention to provide an improved gyroscope suspension system of the type described, in which the plane of the gimbal ring of the gyroscope ismaintained approximately normal to the spin axis of the gyroscope for all attitudes it is mounted.

of the vehicle on which In accordance with the invention, a system for universally supporting a gyroscope from a mobile vehicle comprises a main gimbal ring support for the gyroscope having a first pivotal axis and a second pivotal axis normal thereto and an auxiliary gimbal ring supporting the first ring and having a pivotal axis normally coinciding with the first pivotal axis. The system also includes power means for rotating the auxiliary gimbal ring about its pivotal axis, means responsive to rotation of the main gimbal ring about the first pivotal axis for controlling the power means to cause the auxiliary gimbal ring to position the main ring to maintain the rotation thereof about the first axis within predetermined limits, and means responsive to rotation of the auxiliary ring about the second pivotal axis through the normal to the plane of the main ring for reversing the sense of action of the controlling means.

For a better understanding of the invention, together with other and. further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, while its scope will be pointed out in the appended claims.

Referring now to the drawing,

Fig. l is a. schematic representation of a system embodying the invention for universally supporting a gyroscope from a mobile vehicle;

Fig. 1a is a cross-sectional detail of a pickup mechanism embodied in the system of Fig. 1;

Fig. 2b is a schematic representation of the sensing switch suitable for use in the system of Fig. 1; while Figs. 2a, 2b, 2c and 2d are circuit diagrams of modified followup systems for controlling the auxiliary gimbal ring of the system of Fig. 1.

Referring now to Fig. 1 of the drawing, there is represented in schematic form a system for universally supporting a gyroscope In from a mobile vehicle and embodying the invention. This system comprises main gimbal ring support H for the gyroscope l0 having a pair of pivotal shafts Illa establishing a pivotal axis a about which the gyroscope III is pivotally supported from ring II. The ring H is pivotally supported from a pair of pivotal shafts Ha, Ha definin a second pivotal axis b about which the ring II is pivotally supported. The axes a and b are normal to each other and normally lie in a, plane normal to the spin axis of the gyroscope I ii. The system also includes an-auxiliary gimbal ring l2 supporting the main ring I l and having a pivotal axis 0, about which it is pivotally supported, normally coinciding with the pivotal axis a of gyrorespectively, to form,a,double,-nole.doub

3 'scope Ill. The auxiliary gimbal ring I2 is provided with power means such as a reversible motor I3 for rotating it about its pivotal axis 0. The ring I2 may be supported from the shaft of the motor I3 and from an auxiliary pivotal shaft 5 I2a mounted in a standard I4 and is preferably mounted so that its pivotal axis, .ciscanllroxia mately parallelto-qtheelongitudinnlaaxis of .tlle'c Vehicle.

The system of the invention also includes o means, such as a reversing switch I5, responsive to rotation of the main gimbal ring zligaboutits, axis a for controlling the power means, for ex-..- ample for energizing the motor I 3in, Such asense W as to cause the auxiliary gimhallltlng lg,to posi tion the main gimbal ring I I andto maintain the rotation thereof about the axis a within predetermined limits, preferably to maintain the main-1 ring II approximately normal to the spin axis, of the gyroscope. A cletailtof the reversing switch 20 I5, whichmay be, of conventional construction, is shown in- Fig. l nfrom which" it' is" seen that it comprises a: pair; of; outer-contacts I5'a; 1512" and=a central;movable'contact: I'5c 'operable by anarrn IIlb.- on shaft IIlato close a circuit'with '2 either of;.the contacts; I 5:; or e I 5b inaccordance with;the dirootion ;of rotation of the ring I on which the ,switchis supported'relative to the pivotalgshaftllla; The. reversing motor I3 is con; neotedtobeenereized rom suitable supp y, 30 mina s .I fithrouehon .or the. othe of the; C011? tactsvof, therev rsing swit h. I.5:iand: througna. econdreversing or. .ensing.,-s witoh.. II to. b do? s ribed The systemtalsosinoludes. means, such the-3a reversing, switch I 1; injcascade. with, therey rsing. switch. II 5- and responsive torotation. of 1 the. v, auxiliary ringlzalaout. itsipivotal axisb throu h, thejnormal totheplane of, the main imbaL ring...

I thatisthrough thewertioalafor rerersingth 40,. senserof' actiontof the, firstrevcrsinQ switch. 1.5. Themeversing switchJZImay be 'ofitheponsttuce tion 1, shown in. Fig. 1b, ,.comprising. a pair. of movable contacts wa Ilb.cooperating withtwo. pairs of stationary contacts IIc.,.. fldgandIJQJJf, 4o

lesthltow reversingswitch. .Thelmovablecontactsgl la and I'll; areadapted-to .heactuatcdby atfollowen I'Ig.,. actuated .by; 340311}. I liamountedson an. extension. ofrthepivot shaft I Ia; ,Theswitchl (is provided with input terminals .111 andaoutnut. terminals. 7 921 In considering 5 the: operation of I; the; .-system,.- described, it will be assumed that initially-the: vehicle; on- .which thergyroscope systemtis sup 5. ported thaszaitsmormal attitude. so that-,the-pl-ane, includingythe pivotal-1 axessa. and btof. athetmaino; gimbal ring I'Iisnormal OjthQgSpil'LaXiSpof 'bhfi gyroscope; I II and i the gflXi-Sfi w; coincides; with; axis 0 of the auxiliary-gimbal ;-;ring-; I2. If: now-.- 60,, thejvehiol o s n oan-ext emeha k s-rollethe. i neneimbal ring: s wi lzr atefthrou h theee11- sno d gran le about-the a so; .and,--in;such;. p sition, th ..-.sbehaviour ,of th6sylT0 l e ends; to become erratic and; unreliablos Under this; condition; the z-switch I operates to clos e ;.a: 0; cuitthrouehonerof itsput ri contacts.- I 5axand lfib'rand itsgmovablecontact lfio which;--energizes;the I motor. -I 3vto rotate,the;auxiliarv-gimbal sringvl 2,; and with it themain-gimbal wing. I;I about. the; .70V pivotal axis. c tonosition. or: restoreethe main. e m el ring I to its. norma attitudeandto. mains. tain the rotation thereof,,. about ,,its pivotal; axis,

a with n. p edete minedllimits. he, action .dec. scribed ,plus. the. .free... pivotaLmQtmn. of. ".the. .75..

auxiliary gimbal ring I 2 relative to the main gimbal ring II about the pivotal axis b is efiective to maintain the plane of the main gimbal ring II substantially normal to the spin axis of the gyroscope and thus insure accurate and reliable operation.

If the,gyroscope., system ,d es,crihed,is, mounted on amaircratt Or other mo ile ve icle. thei n itudinal axis of which, during maneuvering, may undergo extreme angular movements even through the normal to the plane of the main gimbaleringi II',: that.-.is through the vertical, the sense of the control efiected by the reversing switch ,I,5,,,rever ses That is, in such extreme attitudes,. rotatiomof; the main gimbal ring H about:aits-.=-axis; av operates the reversing switch I5 in such a sense as to cause the motor IE to drive' the auxiliary=gimbal ring I2 in such sense as toincrease, rather than decrease, the rotation of the gimbal ring II from its normal attitude. h the .improvedi x osc pe. upporting system d scribed; howeven. hes versinguswitch .IJitis. efieotiveu t ese nditionsto intr duce. reyersaloi the c onnec tion oi theirnotor, ltito the pply circuit, termin ls 7 I 6. sons. t reversethe... sense of action of the fi'rst .re ersing s witch This. resultis. procured. l y,.,shai ing. the. camJ 7h of the reversing. switch I 1, 'sothahit. actuates, the; ovablecontaot 111, lJb,thereof,from ne rosin. tion to.v the; other whenevert-the... attitude otthe. vehicle ,issuch .as .to... cause. theauxiliary. s mhall. ring. I 2,,to pass .through,.the ,normal .to the. plane... of .the main. gimbals. ring II that is, .whenever. it pas es thr u h he. vertical,vv

, It. is..note hat. thecamrllh oithei witchll. has. appreciable ,slopingportions, between the por tionscorresponding .to the twompsitions, otthe; switch. .In.applications ,in .whicn-ahigh degree of. precision .of,the,contr.ol:system, ishotrequired, ,itheu, Switch-may. be, designed,,so,,that,., over, the;

greaterpartoftheseslopin portionsrthemovable contacts.- I la .and. I lb, are.. in ,neutraltposition. so; that; neithencircuit isclosed and, -the follow-up system. is inactive.- These- -sl oping portions. are: 1 adjusted,,to correspond: to the position oft-the. auxiliary vgimbal ,rin g II approximately. in, they verticalandoi eitherasenseras itris .notnecessaryz tocausel-a.constantoperationoi theswitch -I 'I and; I reversal :01 the motor, I 3 it the-craft :ison sating with, longitudinal attitude. of one: sense or i the; I other; in .the ,regiom of the vertical.

In. Fig. 2a is schematicallyrepresented armadafi cl form of. hacontrolcireuit:of the.;syst m-poi: Fig,: 1. particularly; suitable fol?! roperating from .directwurrent ,supplyscircuit terminals-:20, 2 0.1,; iIm; thistcase,,thereis connected -,a cross,,-.the:terminals; flra-yoltage dividina resistor. 2 hav-i-na an .67%." tricalw midetap 2 .I a.: The? reversing -switch 1 H (is; connected-acrosstheterminals L2II-andits output: terminals: I U. are; connected to sthe, outer; tacts; oittherswitoh I-,5.-. There, is provided/ ap;- auxi1iary; ,-polarizedirelay;ikonereimdriromgthe upnlxf-t rminalsr- 0; that.connection. b.etweentthe movable; contact,,-oi- -.theswitch .I 5.- andithe ,mid point hie-oi resistozr zl The mama. $2; vided-w-itnouter stationarit contacts-:mdr a1.- en tralmmovabler.-conta,ct, conneeted to excites theta motor I3 ion-rotation in either.direotioni speoifi= a m the controLmotor. I3. isoonnecteabetv een themldp intzl alof. resistor, 21 andttheumoyable. contact. oI.,;.re1ay,.=22. r. It .,wil1 be-iunderstoodthao the, reversing; switches; I5... and; L. are.-, to .be-.. 'Jnountedas t n the. systennoiff'is, andathataasw insthe-s stemlof. F

swi ch -I 5.xcomprisesra, two-position switch connected to be-actuabethm :1,

one position or the other in accordance with the direction of, and in response to, rotation of the main gimbal ring II about the pivotal axis a. The switch I5 is effective to control the polarity of excitation of the relay 22 from the supply terminals 20 and thus to control the motor I3 to rotate the auxiliary ring I2 about its pivotal axis to compensate for rotation ofv the gimbal ring II about the axis a. The operation of the system of Fig. 2a is in all respects similar to that of Fig. 1, the use of the midpoint voltage-dividing resistor 2| and the polarized relay 22 adapting the system for operation with the reversible direct-current motor I3.

In Fig. 2b, there is represented schematically the circuit diagram of a modification of the system of Fig. 2a in which the'double-pole doublethrow reversing switch II is replaced by a singlepole double-throw reversing switch 23 which may be in all respects similar to the switch I5 of Fig. 1. In this case, a second voltage-divider resistor 24 is connected between the movable contact of the switch 23 and the midpoint 2Ia of voltage-divider resistor 2| while the relay 22 connected to control the control motor I3, as in the system of Fig. 2a, is connected between the midpoint 24a of resistor 24 and the movable contact of the switch I5. In this arrangement, the single-pole reversing switch 23 and the voltagedivider resistor 24 take the place of the double pole reversing switch I! of Fig. 1 and the switch 23 constitutes a second two-position switch in series with the switch I5 and responsive to rotation of the auxiliary ring l2 through the vertical for reversing the sense of action of the twoposition switch I5. The operation of the system is similar to that of Fig. 1.

In some cases, it is desirable to maintain the plane of the main gimbal ring I I accurately normal to the spin axis of the gyroscope. This is facilitated by the proportional follow-up system of Fig. 2c in which the reversing switch I5 is replaced by a rotary transformer 25 comprising a primary or stator winding 25a and a salient pole secondary or rotor winding 25b rotatable relative to the winding 25a. In this arrangement, the windings 25a and 25b are individually mounted on the gyroscope pivot shaft Illa and on the main gimbal ring II, or vice versa. The signal output of the winding 25b appears at the terminals 250 and is connected through the reversing switch l1 and an amplifier 26 to the control motor I3. In this arrangement, the signal developed by the rotary transformer 25 at the terminals 250 is of a polarity dependent upon, and of an amplitude proportional to, rotational movement of the main gimbal ring II about its axis a. This signal, as modified by the sensing or reversing switch I1, is applied to the amplifier 26 to drive the motor I3 in a sense and at a rate proportional to the polarity and amplitude of the signal at the terminals 250, that is in a sense and at a rate proportional to the sense and angular rotation of the ring II about its axis a. This system provides maximum speed and accuracy of control since, the greater the initial rotation of the ring II about the axis a, the greater the speed of operation of the motor I3 to actuate the auxiliary ring I2 to return the ring II to its normal attitude.

In case the system of the invention is installed on a vehicle such as an aircraft having other instruments or controls stabilized by the same gyroscope and in case the aircraft maneuvers through extreme angles passing through the vertical, the other gyroscopic instruments or controls may reverse their sense without changing their azimuthal position relative to the earth, resulting in 180 azimuthal errors. These errors may also be corrected by means of a system embodying the invention as shown in the modified circuit of Fig. 2d which is designed for operation from direct-current supply terminals 2t, 25 In the system of Fig. 2d the reversing switch i5 is replaced by a simple on-off switch 33 in which the contacts are closed for positions of the gimbal ring II on one side of neutral and open for positions on the other side of neutral. This switch is connected to energize a relay 3I from the supply terminals 2:], 2B, the relay 3i having contacts equivalent to a double-pole doublethrow reversing switch. Similarly, the reversing switch I] of the system of Fig. l is replaced by a simple ofi-on switch 32 which is connected to energize relays 33, 34 in series across the supply circuit terminals 23. The relay 33 also is provided with contacts equivalent to a double-pole double-throw reversing switch. The control motor is energized from supply circuit terminals 20, 2!) through the contacts of relays 3i and 32 in series so that the control of the motor I3 is in all respects similar to that of the system of Fig. 1.

The system of Fig. 2d is indicated as including also a gyro-compass repeating system comprisinga stabilized compass transmitter 35 and a compass repeater 36 interconnected through the contacts of relay 34, which are also the equivalent of a double-pole double-throw reversing switch. In the system of Fig. 2d the maneuvering of the Vehicle so that the axis 0 of Fig. 1 passes through the normal to the plane of the gimbal ring II, that is the vertical, is effective to close the contacts 32 to energize the relays 4 33 and 34, thus reversing the sense of operation of the control motor I3. Simultaneously the connections between the compass-transmitter unit 35 and the compass-repeater unit 36 are reversed to compensate for the reversal of azimuth of the vehicle without a corresponding reversal in the azimuthal position of the stabilized compass transmitter.

In applications of the gyro-supporting system of the invention to devices such as gyro-compass systems such as the system 35, 3'6 in which no azimuthal rotation of the gyroscope casing can be tolerated, the axis 0 of the auxiliary ring 12 must be substantially parallel to the longitudinal axis of the vehicle.

Where there have been described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modications may be made therein without depart ing from the spirit or scope of the invention.

What is claimed as new is:

1. A system for universally supporting a gyroscope from a mobile vehicle comprising, a main gimbal ring support for said gyroscope having a first pivotal axis and a second pivotal axis normal thereto. an auxiliary gimbal ring supporting said first ring and having a pivotal axis normally coinciding with said first pivotal axis, power means for rotating said auxiliary gimbal ring about its pivotal axis, means responsive to rotation of said main gimbal ring about said first pivotal axis for controlling said power means to cause said auxiliary gimbal ring to position said main ring to maintain the rotation thereof about said first axis within predetermined limits, and

Disclaimer W. Phaz'r, Lyndhurst, N. J. UNIVERSAL Gnmecom-Susnm- Patent dated. May 10, 1949. Disclaimer filed Oct. 22,

1951, by the inventqr, the assignee, Faz'mhild Uamem and I nstrument Corpomtz'on, assentmg.

ms 1, 3, and 4 of said patent.

Hereby enters this disclaimer to clai [Oyfieial Gazette N o'uember 2'7, 1,951.]

SIGN SYSTEM, 

